1. Field of the Invention
The invention pertains to rotary joints of the type used to introduce or remove steam, water or the like into or from a rotating heating or cooling drum such as utilized in the paper, paperboard and fabric web fabricating arts.
2. Description of the Related Art
Rotary joints have long been used to introduce steam into rotating drums of the type employed in the paper making arts, and such joints may simultaneously introduce steam and remove the condensate. Likewise, rotary joints are employed to introduce and remove water from drums used for cooling purposes. The rotating drums in paper making mills are usually of a large diameter, three or four feet in dimension, and such drum size permits the rotary joints of adjacent drums to be spaced apart by several feet providing sufficient clearance between adjacent joints to provide access and permit joints to be disassembled or otherwise serviced. However, large printing installations employ relatively small rollers which are temperature controlled by fluid medium introduced into the drums or rollers, and as the drums are of small diameter, the rotary joints of adjacent drums must, necessarily, be in close proximity to each other.
Rotary joints in close proximity to each other are very difficult to service in that the necessary conduits supplying the joint with medium, or removing used medium therefrom, cause the access to such joints to be limited significantly complicating joint removal or installation, servicing and removal procedures. In the past, in those installations where rotary joints must, necessarily, be closely spaced together, it is necessary to utilize nipples and other joint structure of different lengths to "stagger" joints, and other compromises of installation are utilized to overcome the lack of space. As previous rotary joint constructions require at least partial disassembly of the body to permit the body and nipple to be removed, or if the nipple is mounted with a quick-connect fitting on the drum journal, a lack of accessibility to the joint structure significantly complicates joint servicing. While a quick-connect attachment of the nipple to the drum journal simplifies joint removal if adequate clearance between adjacent joints is available, such type of nipple connection is of little advantage in closely confined installations in that the quick-disconnect structure is located between the joint body and the drum, and the joint body limits access to the quick-disconnect nipple coupling.